The present invention relates to improvement in plastic sliders for opening and closing plastic reclosable fasteners or zippers on plastic bags and the like and particularly to flexible plastic sliders for assembly with the zipper by transverse movement.
Plastic zippers with plastic sliders are well known in the art. The type of plastic zippers to which the present invention relates have profiles that include a pair of male and female fastener elements in the form of reclosable interlocking rib and groove elements with a slider for opening and closing the rib and groove elements. In the manufacture of plastic-film bags, a pair of these male and female fastener elements extend along the mouth of the bag and these male and female elements are adapted to be secured in any suitable manner to the flexible walls of the plastic-film bags.
Sliders for opening or closing the reclosable fasteners are essentially U-shaped and are adapted to be assembled with the zipper by threading them onto the end of the zipper or by a relative transverse maneuver. To facilitate the transverse maneuver, some of the sliders have been provided with folding sidewalls and others have been assembled on the zipper from multiple parts. In some instances, the multiple parts of the plastic slider have been ultrasonically welded together and in other instances the multiple parts of the slider have been constructed to be snapped together. In each of these prior art multi-part plastic sliders the various parts have been assembled together in a direction transverse to the axis of the zipper. Examples of patents showing multi-part plastic sliders are shown in U.S. Pat. No. 5,007,142 - Herrington, U.S. Pat. No. 5,007,143 Herrington and U.S. Pat. No. 5,020,194 - Herrington et al. Examples of patents showing plastic sliders with folding sidewalls are shown in U.S. Pat. No. 5,010,627 - Herrington et al, 5,063,644 - Herrington et al and U.S. Pat. No. 5,070,583 - Herrington.
It would be desirable to provide a flexible plastic slider having sidewalls normally diverging outwardly and spaced apart a distance adequate for transverse installation over the profile elements of a zipper with rigidizing structure on the slider to move the sidewalls into and retain them in an assembled position on the zipper to prevent the slider from being lifted off the zipper.